I'm going to update my three male betta fish to a divided ten gallon, but i have a few questions. If i get two dividers from Petsmart, they dont have holes, so i assume I'd need a sponge filter for each section? If I make them myself, I could make them with holes in them so i would only need one filter, right? which option would be best? also which sponge filter would be best? link it, if possible. Thanks.